Figure 1:

(A) Schematic diagram of the multilevel SLIM. (B) The layout of level 1. (C) The layout of level 2. (D) The layout of levels 3, 5, and 7. (E) The layout of levels 4, 6, and 8.

(A) Schematic diagram of the multilevel SLIM. (B) The layout of level 1. (C) The layout of level 2. (D) The layout of levels 3, 5, and 7. (E) The layout of levels 4, 6, and 8.